BioReady Streptavidin Gold Conjugation Protocol
nanoComposix BioReady™ Streptavidin Gold can be conjugated to biotinylated proteins through affinity interactions. The avidin-biotin interaction is one of the strongest non-covalent affinity interactions. BioReady gold nanoparticles with Streptavidin are prepared by covalently attaching the tetrameric protein to the surface of the functionalized nanoparticles, with excellent retention of biotin-binding activity.
Contact us for inquiries regarding custom conjugation, technical support, or determining which nanoparticle is right for your application.
Material Information & Storage
BioReady Streptavidin-Gold is provided at OD 10 in 1x PBS, 0.5% BSA, and 0.05% azide. Store the particles at 4 °C. Do not freeze. Thoroughly shake contents to disperse particles if settling occurs.
Additional Materials Required
- Biotinylated reagent for attachment
- Biotin quantitation kit/HABA assay
- Biotin (optional)
- Wash/storage buffer (1x PBS with 0.5% 20K MW PEG, or another buffer of choice)
- Centrifuge tubes
- Centrifuge
Streptavidin-Biotin Conjugation Ratio
For conjugation of biotinylated reagent to BioReady Streptavidin Gold, the optimal ratio will depend on how much biotins are available. In many cases, there may be multiple biotin moieties per protein. To determine the amount of biotin on your protein, run a biotin quantitation/HABA assay.
Conjugation Protocol
The following procedure provides some general guidance for conjugating 1 mL of OD 10 BioReady™ Streptavidin Gold to biotinylated antibody. For larger volumes, centrifugation speed and time may need to be adjusted.
Conjugation procedures may vary depending on the biotinylated reagents and other conditions specific to the different types of application.
Note: Prior to conjugation with biotin, Streptavidin Gold solution can be exchanged into another buffer of choice by centrifuging the particles, remove the supernatant, then resuspend in the desired buffer.
- Aliquot BioReady Streptavidin Gold in an Eppendorf tube or other reaction vessel.
- To this solution, add biotinylated IgG. The amount of biotinylated reagent added will have to be optimized for each antibody or application.
- Incubate at room temperature for 30 minutes with end-over-end rotation or rocking. Incubation time can also be adjusted to optimize performance.
- To prevent potential cross-linking of particles, quench any remaining avidin sites with an excess of biotin (optional).
- Centrifuge the conjugate at the specified speed and time in the table, carefully remove the supernatant, and resuspend in the wash/storage buffer. Repeat this wash step 3× to remove any excess biotinylated IgG in the solution.
- For final resuspension, bring the conjugate to the desired storage concentration.
- Store conjugate at 4 °C. Do not freeze.
| Centrifugation Speed) | Time (minutes) | |
|---|---|---|
| 40nm Gold Nanospheres | 3500 | 10 |
| 150nm Gold Nanoshells | 2000 | 5 |
What is the shelf life of BioReady™?
What is the shelf life of the conjugates?
Can I conjugate any type of antibody or protein?
How is streptavidin attached to the surface of the gold particle?
Is there a test to confirm my conjugates are functional?
How do I optimize my conjugate?
What can I do to improve conjugate release and flow on a lateral flow test?
